MICREL MIC921BC5

MIC921
Micrel, Inc.
MIC921
45MHz Low-Power SC-70 Op Amp
General Description
Features
The MIC921 is a high-speed operational amplifier with a
gain-bandwidth product of 45MHz. The part is unity gain
stable. It has a very low 300µA supply current, and features
the IttyBitty™ SC-70 and SOT-23-5 package.
Supply voltage range is from ±2.5V to ±9V, allowing the
MIC921 to be used in low-voltage circuits or applications
requiring large dynamic range.
The MIC921 is stable driving any capacitative load and
achieves excellent PSRR and CMRR, making it much easier
to use than most conventional high-speed devices. Low
supply voltage, low power consumption, and small packing
make the MIC921 ideal for portable equipment. The ability
to drive capacitative loads also makes it possible to drive
long coaxial cables.
•
•
•
•
•
•
•
•
45MHz gain bandwidth product
61MHz –3dB bandwidth
300µA supply current
SC-70 or SOT-23-5 packages
3200V/µs slew rate
Drives any capacitive load
112dB CMRR
Unity gain stable
Applications
•
•
•
•
•
Video
Imaging
Ultrasound
Portable equipment
Line drivers
Ordering Information
Part Number
Standard
Marking
MIC921BM5
A38
MIC921BC5
A38
Pb-Free
MIC921YC5
Marking
Ambient Temperature
Package
–40ºC to +85ºC
SOT-23-5*
–40ºC to +85ºC
SC-70-5
A38
* Contact factory for availability of SOT-23-5 package.
Note: Underbar marking may not be to scale.
Pin Configuration
IN– V– IN+
3
2
1
A38
4
5
OUT
V+
Functional Pinout
IN–
Part
Identification
3
SOT-23-5 or SC-70
V– IN+
2
1
4
5
OUT
V+
SOT-23-5 or SC-70
Pin Description
Pin Number
Pin Name
Pin Function
1
IN+
Noninverting Input
2
V–
Negative Supply (Input)
3
IN–
Inverting Input
4
OUT
Output: Amplifier Output
5
V+
Positive Supply (Input)
IttyBitty is a trademark or Micrel, Inc.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 2006
1
MIC921
MIC921
Micrel, Inc.
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Supply Voltage (VV+ – VV–) ........................................... 20V
Differentail Input Voltage (VIN+ – VIN–) ........... 4V, Note 3
Input Common-Mode Range (VIN+, VIN–) ............VV+ to VV–
Lead Temperature (soldering, 5 sec.) ........................ 260°C
Storage Temperature (TS) ......................................... 150°C
ESD Rating, Note 4 ................................................... 1.5kV
Supply Voltage (VS) .........................................±2.5V to ±9V
Junction Temperature (TJ) .......................... –40°C to +85°C
Package Thermal Resistance
SC70-5 .............................................................. 450°C/W
SOT23-5 ............................................................ 260°C/W
Electrical Characteristics (±5V)
V+ = +5V, V– = –5V, VCM = 0V, RL = 10MΩ; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; unless noted.
Symbol
Parameter
VOS
Input Offset Voltage
IB
Input Bias Current
VOS
VOS Temperature Coefficient
IOS
Input Offset Current
VCM
Input Common-Mode Range
CMRR
Common-Mode Rejection Ratio
PSRR
Power Supply Rejection Ratio
AVOL
Large-Signal Voltage Gain
VOUT
Maximum Output Voltage Swing
Condition
Min
Unity Gain-Bandwidth Product
PM
Phase Margin
Max
Units
5
mV
1
0.13
0.06
CMRR > 72dB
–3.25
µV/°C
0.6
µA
0.3
µA
+3.25
V
–2.5V < VCM < +2.5V
75
87
dB
95
105
dB
RL = 2k, VOUT = ±2V
70
84
dB
85
dB
±3.5V < VS < ±9V
RL = 100Ω, VOUT = ±1V
positive, RL = 2kΩ
+3.0
positive, RL = 200Ω
+1.5
negative, RL = 2kΩ
GBW
Typ
0.43
3.7
–3.7
negative, RL = 200Ω, Note 5
3.0
–2.5
AV = 1, CL = 1.7pF
AV = 1, RL = 1kΩ, CL = 1.7pF
V
–3.0
V
V
–1.0
V
37
MHz
46
°
53
MHz
1500
V/µs
57
mA
BW
–3dB Bandwidth
SR
Slew Rate
C=1.7pF, Gain=1, VOUT=5V, peak to peak,
negative SR = 1300V/µs
ISC
Short-Circuit Output Current
source
45
sink
20
IS
Supply Current
No Load
0.30
Input Voltage Noise
f = 10kHz
12
nV√Hz
Input Current Noise
f = 10kHz
0.7
pA√Hz
40
mA
0.50
mA
Electrical Characteristics
V+ = +9V, V– = –9V, VCM = 0V, RL = 10MΩ; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; unless noted
Symbol
Parameter
VOS
Input Offset Voltage
VOS
Input Offset Voltage
Temperature Coefficient
IB
Input Bias Current
Condition
Min
Units
5
mV
0.13
Input Offset Current
Input Common-Mode Range
CMRR > 75dB
CMRR
Common-Mode Rejection Ratio
–2.5V < VCM < +2.5V
MIC921
Max
0.4
1
IOS
VCM
Typ
0.06
2
–7.25
75
87
µV/°C
0.6
µA
0.3
µA
+7.25
V
dB
April 2006
MIC921
Micrel, Inc.
Symbol
Parameter
Condition
PSRR
Power Supply Rejection Ratio
AVOL
Large-Signal Voltage Gain
±3.5V < VS < ±9V
VOUT
Maximum Output Voltage Swing
GBW
Unity Gain-Bandwidth Product
RL = 2k, VOUT = ±3V
RL = 100Ω, VOUT = ±1V
positive, RL = 2kΩ
Min
Typ
95
105
dB
75
86
dB
92
dB
+6.5
7.6
V
negative, RL = 2kΩ
–7.6
Max
–6.2
Units
V
AV = 1, CL = 1.7pF
45
MHz
40
°
AV = 1, RL = 1kΩ, CL = 1.7pF
61
MHz
3200
V/µs
PM
Phase Margin
BW
–3dB Bandwidth
SR
Slew Rate
ISC
Short-Circuit Output Current
IS
Supply Current
No Load
0.36
Input Voltage Noise
f = 10kHz
12
nV√Hz
Input Current Noise
f = 10kHz
0.7
pA√Hz
C=1.7pF, Gain=1, VOUT=5V, peak to peak,
negative SR = 2500V/µs
source
40
59
mA
sink
25
45
mA
0.6
mA
Note 1.
Exceeding the absolute maximum rating may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3.
Exceeding the maximum differential input voltage will damage the input stage and degrade performance (in particular, input bias current is
likely to change).
Note 4.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
Note 5.
Output swing limited by the maximum output sink capability, refer to the short-circuit current vs. temperature graph in “Typical Characteristics.”
April 2006
3
MIC921
MIC921
Micrel, Inc.
Test Circuits
V+
10µF
Input
BNC
V+
0.1µF
50Ω
R2
5k
0.1µF
10k
10k
10k
2k
3
1
5
MIC921
BNC
4
Input
Output
Input
R1 5k
BNC
3
R7c 2k
2
1
R7b 200ΩΩ
R7a 100
50Ω
5k
50Ω
All resistors:
1% metal film
R3
200k
0.1µF
All resistors 1%
10µF
0.1µF
4
2
BNC
Output
0.1µF
R5
5k
10µF
V–
R4
250Ω
 R2 R2 + R 5 + R4 
VOUT = VERROR 1 +
+

 R1

R7
V–
PSRR vs. Frequency
100pF
5
MIC921
R6
0.1µF
BNC
10µF
CMRR vs. Frequency
V+
V+
10µF
10pF
R1
20Ω
R3 27k
S1
S2
R5
20Ω
R2 4k
3
3
1
R4 27k
10µF
5
0.1µF
MIC921
2
10pF
4
BNC
0.1µF
To
Dynamic
Analyzer
VIN
0.1µF
MIC921
2
300Ω
4
0.1µF
50Ω
1k
VOUT
FET Probe
CL
10µF
10µF
V–
V–
Closed Loop Frequency Response Measurement
Noise Measurement
MIC921
1
5
4
April 2006
MIC921
Micrel, Inc.
Typical Characteristics
Offset Voltage vs.
Common-Mode Voltage
2.20
2.00
V± = ±2.5V
1.80
–40°C
1.60
1.40
+25°C
1.20
1.00
+85°C
0.80
0.60
0.40
0.20
0
-900 -540 -180 180 540 900
COMMON-MODE VOLTAGE (V)
Output Voltage vs.
Output Current (Sinking)
V± = ±5V
–40°C
25°C
85°C
-45.0
-40.5
-36.0
-31.5
-27.0
-22.5
-18.0
-13.5
-9.0
-4.5
0
0.5
0
-0.5
-1.0
-1.5
-2.0
-2.5
-3.0
-3.5
-4.0
-4.5
-5.0
OUTPUT CURRENT (mA)
Output Voltage vs.
Output Current (Sourcing)
0.5
V± = ±9V
0 85°C
-0.5
25°C
-1.0
-1.5
–40°C
-2.0
-2.5
-3.0
-3.5
-4.0
-4.5
-5.0
0 8 16 24 32 40 48 56 64 72 80
OUTPUT CURRENT (mA)
April 2006
0.35
0.30
V± = ±9V
V± = ±5V
V± = ±2.5V
0.25
0.20
0.15
0.10
-40 -20 0 20 40 60 80 100
TEMPERATURE °C)
(
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Offset Voltage vs.
Common-Mode Voltage
V± = ±5V
–40°C
+85°C
+25°C
COMMON-MODE VOLTAGE (V)
Output Voltage vs.
Output Current (Sinking)
0.9
V± = ±9V
0
-0.9
-1.8
-2.7
25°C
-3.6
-4.5 85°C
–40°C
-5.4
-6.3
-7.2
-8.1
-9.0
-50-45-40-35-30-25-20-15-10 -5 0
OUTPUT CURRENT (mA)
Short Circuit Current vs.
Supply Voltage (Sinking)
7
0
–40°C
-7
25°C
-14
-21
-28
-35 85°C
-42
-49
-56
-63
-70
2.0 3.4 4.8 6.2 7.6 9.0
SUPPLY VOLTAGE (V)
5
0.42
0.40
0.38
0.36
0.34
0.32
0.30
0.28
0.26
0.24
0.22
0.20
2.5
Supply Current
vs. Supply Voltage
+85°C
+25°C
–40°C
3.8 5.1 6.4 7.7
SUPPLY VOLTAGE (V)
9
Offset Voltage vs.
Common-Mode Voltage
2.2
2
1.8
1.6
1.4
1.2
+25°C
1
0.8
0.6
0.4
0.2
0
V± = ±9V
–40°C
+85°C
-7.40
-5.92
-4.44
-2.96
-1.48
0
1.48
2.96
4.44
5.92
7.40
1
0.95
0.9
0.85
V± = ±2.5V
0.8
0.75
0.7
V± = ±5V
0.65
V± = ±9V
0.6
0.55
0.5
-40 -20 0 20 40 60 80 100
TEMPERATURE °C)
(
Supply Current
vs. Temperature
-3.4
-2.7
-2.0
-1.4
-0.7
0.0
0.7
1.4
2.0
2.7
3
Offset Voltage
vs. Temperature
COMMON-MODE VOLTAGE (V)
Output Voltage vs.
Output Current (Sourcing)
5.5
V± = ±5V
5.0
4.5
4.0 85°C
25°C
3.5
3.0
2.5 –40°C
2.0
1.5
1.0
0.5
0
0 8 16 24 32 40 48 56 64 72 80
OUTPUT CURRENT (mA)
110
100
90
80
70
60
50
40
30
20
10
0
Short-Circuit Current vs.
Supply Voltage (Sourcing)
–40°C
25°C
85°C
2
3.4 4.8 6.2 7.6
SUPPLY VOLTAGE ±V)
(
9
MIC921
MIC921
Micrel, Inc.
0.12
V± = ±5V
0.10
0.08
V± = ±9V
0.06
0.04
0.02
0.00
-40 -20 0 20 40 60 80 100
TEMPERATURE °C)
(
50
40
30
20
10
0
-10
-20
-30
-40
-50
100k
Open-Loop Gain
vs. Frequency
50
40
30
20
10
0
-10
-20
-30
-40
-50
100k
V± = ±5V
50pF
100pF
1.7pF
200pF
400pF
600pF
1000pF
100M
10M
1M
FREQUENCY (Hz)
Open-Loop
Frequency Response
225
180
135
90
45
0
-45
-90
-135
-180
-225
PHASE (°)
100
80 V± = ±9V
Phase
(100Ω)
60
40
(no load)
20
0
(100Ω)
-20
Gain
-40
-60
-80
-100
FREQUENCY (Hz)
Gain Bandwidth and Phase
Margin vs. Load
40
V± = ±9V
35
30
25
Phase Margin
10
5
Gain Bandwidth
10
0
0
100
200
300
400
500
600
700
800
900
1000
0
CAPACITIVE LOAD (pF)
MIC921
200pF
400pF
600pF
800pF
1000pF
100M
10M
1M
FREQUENCY (Hz)
V± = ±9V
50pF
100pF
1.7pF
200pF
400pF
600pF
1000pF
100M
10M
1M
FREQUENCY (Hz)
Phase Margin
40
35
100pF
200pF
400pF
600pF
800pF
1000pF
100M
10M
1M
FREQUENCY (Hz)
V± = ±5V
Gain Bandwidth
5
2
4
6
8
10
SUPPLY VOLTAGE (V)
Voltage Noise Density
vs. Frequency
60
40
Phase Margin
30
15
10
25
225
180
135
90
45
0
-45
-90
-135
-180
-225
50
30
20
20
Gain Bandwidth
10
0
0
CAPACITIVE LOAD (pF)
2.5
Current Noise Density
vs. Frequency
2.0
50
40
1.5
30
1.0
20
0.5
10
0
10
1.7pF
Gain Bandwidth and Phase
Margin vs. Load
35
20
0
50pF
100
80 V± = ±5V
Phase
(100Ω)
60
40
(no load)
20
0
(100Ω)
-20
Gain
-40
-60
-80
-100
1M
10M
100M
100k
FREQUENCY (Hz)
25
30
V± = ±9V
Open-Loop
Frequency Response
Open-Loop Gain
vs. Frequency
40
60
20
15
100pF
45
50
30
20
50
70
40
1.7pF
Gain Bandwidth and Phase
Margin vs. Supply Voltage
60
PHASE MARGIN (°)
45
50pF
50
40
30
20
10
0
-10
-20
-30
-40
-50
100k
PHASE (°)
0.14
V± = ±5V
Closed-Loop Gain
vs. Frequency
PHASE MARGIN (°)
50
40
30
20
10
0
-10
-20
-30
-40
-50
100k
0.16
Closed-Loop Gain
vs. Frequency
0
100
200
300
400
500
600
700
800
900
1000
0.18
Bias Current vs.
Temperature
100
1000 10000 100000
FREQUENCY (Hz)
6
0
10
100
1000 10000 100000
FREQUENCY (Hz)
April 2006
MIC921
Micrel, Inc.
Positive Slew Rate
vs. Supply Voltage
800
Negative Slew Rate
vs. Supply Voltage
1600
1400
700
1400
600
1200
500
1000
400
800
300
600
600
200
400
400
100
200
200
0
0
1600
1400
3
4
5
6 7 8
POSITIVE VOLTAGE ±V)
(
9
Positive Slew Rate
1000
800
0
3500
V± = ±5V
1 2 3 4 5 6 7 8
POSITIVE VOLTAGE±V)
(
9
3000
V± = ±9V
1500
1500
600
1000
1000
400
V± = ±9V
2000
2000
800
Negative Slew Rate
2500
2500
1000
0
LOAD CAPACITANCE (pF)
Positive Slew Rate
3000
1200
V± = ±5V
0
100
200
300
400
500
600
700
800
900
1000
2
1200
Negative Slew Rate
0
0
0
0
100
200
300
400
500
600
700
800
900
1000
500
0
100
200
300
400
500
600
700
800
900
1000
500
0
100
200
300
400
500
600
700
800
900
1000
200
Positive Power Supply
Rejection Ratio
Negative Power Supply
Rejection Ratio
Positive Power Supply
Rejection Ratio
LOAD CAPACITANCE (pF)
120
LOAD CAPACITANCE (pF)
120
V± = ±5V
V± = ±5V
LOAD CAPACITANCE (pF)
120
100
100
100
80
80
80
60
60
60
40
40
40
20
20
20
0
100
120
10k
100k
1k
FREQUENCY (Hz)
1M
Negative Power Supply
Rejection Ratio
V± = ±9V
100
80
60
40
20
0
100
April 2006
10k
100k
1k
FREQUENCY (Hz)
1M
0
100
10k
100k
1k
FREQUENCY (Hz)
1M
Common-Mode Rejection Ratio
100
90
80
70
60
50
40
30
20
10
0
100
V± = ±5V
1k
10k 100k 1M
FREQUENCY (Hz)
7
10M
0
100
V± = ±9V
10k
100k
1k
FREQUENCY (Hz)
1M
Common-Mode Rejection Ratio
100
90
80
70
60
50
40
30
20
10
0
100
V± = ±9V
1k
10k 100k 1M
FREQUENCY (Hz)
10M
MIC921
MIC921
Micrel, Inc.
Functional Characteristics
Small Signal Reponse
Small Signal Reponse
V = ±5V
Av = 1
CL = 1.7pF
OUTPUT
(50mV/div)
OUTPUT
(50mV/div)
INPUT
(50mV/div)
INPUT
(50mV/div)
V = ±9V
Av = 1
CL = 1.7pF
TIME (100ns/div)
TIME (100ns/div)
Small Signal Reponse
Small Signal Reponse
V = ±5V
Av = 1
CL = 100pF
OUTPUT
(50mV/div)
OUTPUT
(50mV/div)
INPUT
(50mV/div)
INPUT
(50mV/div)
V = ±9V
Av = 1
CL = 100pF
TIME (500ns/div)
TIME (500ns/div)
Small Signal Reponse
Small Signal Reponse
V = ±9V
Av = 1
CL = 1000pF
OUTPUT
(50mV/div)
OUTPUT
(50mV/div)
INPUT
(50mV/div)
INPUT
(50mV/div)
V = ±5V
Av = 1
CL = 1000pF
TIME (1s/div)
TIME (1s/div)
MIC921
8
April 2006
MIC921
Micrel, Inc.
Large Signal Response
Large Signal Response
V = ±5V
Av = 1
CL = 1.7pF
OUTPUT
(2V/div)
OUTPUT
(2V/div)
V = ±9V
Av = 1
CL = 1.7pF
Positive Slew Rate = 3230V/µs
Negative Slew Rate = 2950Vµ/s
Positive Slew Rate = 1520V/µs
Negative Slew Rate = 1312V/µs
TIME (25ns/div)
TIME (25ns/div)
Large Signal Response
Large Signal Response
V = ±5V
Av = 1
CL = 100pF
OUTPUT
(2V/div)
OUTPUT
(2V/div)
V = ±9V
Av = 1
CL = 100pF
Positive Slew Rate = 349V/µs
Negative Slew Rate = 181V/µs
Positive Slew Rate = 615V/µs
Negative Slew Rate = 447V/µs
TIME (50ns/div)
TIME (25ns/div)
Large Signal Response
Large Signal Response
V = ±9V
Av = 1
CL = 1000pF
OUTPUT
(2V/div)
OUTPUT
(2V/div)
V = ±5V
Av = 1
CL = 1000pF
Positive Slew Rate = 63V/µs
Negative Slew Rate = 44V/µs
Positive Slew Rate = 85V/µs
Negative Slew Rate = 57V/µs
TIME (250ns/div)
TIME (250ns/div)
April 2006
9
MIC921
MIC921
Micrel, Inc.
Applications Information
Power Supply Bypassing
Regular supply bypassing techniques are recommended.
A 10µF capacitor in parallel with a 0.1µF capacitor on both
the positive and negative supplies are ideal. For best performance all bypassing capacitors should be located as close
to the op amp as possible and all capacitors should be low
ESL (equivalent series inductance), ESR (equivalent series
resistance). Surface-mount ceramic capacitors are ideal.
Thermal Considerations
The SC70-5 package, like all small packages, has a high
thermal resistance. It is important to ensure the IC does not
exceed the maximum operating junction (die) temperature of
85°C. The part can be operated up to the absolute maximum
temperature rating of 125°C, but between 85°C and 125°C
performance will degrade, in particular CMRR will reduce.
An MIC921 with no load, dissipates power equal to the quiescent supply current * supply voltage
The MIC921 is a high-speed, voltage-feedback operational
amplifier featuring very low supply current and excellent
stability. This device is unity gain stable, capable of driving
high capacitance loads.
Driving High Capacitance
The MIC921 is stable when driving high capacitance, making
it ideal for driving long coaxial cables or other high-capacitance loads. Most high-speed op amps are only able to drive
limited capacitance.
Note: increasing load capacitance does reduce
the speed of the device. In applications where
the load capacitance reduces the speed of the
op amp to an unacceptable level, the effect of
the load capacitance can be reduced by adding a small resistor (<100Ω) in series with the
output.
Feedback Resistor Selection
Conventional op amp gain configurations and resistor selection
apply, the MIC921 is NOT a current feedback device.
Also, for minimum peaking, the feedback resistor should have
low parasitic capacitance, usually 470Ω is ideal. To use the
part as a follower, the output should be connected to input
via a short wire.
Layout Considerations
All high speed devices require careful PCB layout. The following guidelines should be observed: Capacitance, particularly
on the two inputs pins will degrade performance; avoid large
copper traces to the inputs. Keep the output signal away from
the inputs and use a ground plane.
It is important to ensure adequate supply bypassing capacitors are located close to the device.
MIC921
(
)
PD(no load) = VV+ – VV- IS
When a load is added, the additional power is dissipated in
the output stage of the op amp. The power dissipated in the
device is a function of supply voltage, output voltage and
output current.
(
)
PD(output stage) = VV+ – VOUT IOUT
Total Power Dissipation = PD(no load) + PD(output stage)
Ensure the total power dissipated in the device is no greater
than the thermal capacity of the package. The SC70-5 package has a thermal resistance of 450°C/W.
TJ(max) – TA(max)
Max. Allowable Power Dissipation =
450°C/W
10
April 2006
MIC921
Micrel, Inc.
Package Information
SOT-23-5 (M5)
SC-70 (C5)
MICREL INC.
2180 FORTUNE DRIVE
SAN JOSE, CA 95131
USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com
This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's
use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2001 Micrel, Inc.
April 2006
11
MIC921